G'morning. On Mon, Jun 24, 2013 at 2:22 AM, peter dalgaard <pda...@gmail.com> wrote: > > On Jun 23, 2013, at 22:30 , Sarah Goslee wrote: > >> Hi, >> >> If you're doing exactly as described below, then you need to add the >> data argument to wilcox.test so R knows where to find beforesmall and >> aftersmall. But if so, that's a rather uninformative error message. >> >> Saraj > > Not really, if you use the formula interface, the rhs is supposed to be the > grouping, as in > > wilcox.test(extra ~ group, data=sleep, paired=TRUE) > > so it's telling you that "aftersmall" does not describe two groups.
Yep, sorry. That was actually my first thought, but then I misread the helpfile. You do still need the data argument, though. :) Sarah > (It is unfortunate, though, that we don't have a formula interface to the > parallel-vector data layout for paired tests. That is the common case, the > sleep data set is a rather rare exception. A formula specification for paired > columns has been talked about; something like cbind(before, after) ~ 1 should > be workable, but nothing has materialized to date.) > > -pd > >> >> On Sun, Jun 23, 2013 at 2:34 PM, ruth parker <parkeractonr...@gmail.com> >> wrote: >>> Hi, >>> I've been trying to run a wilcox paired test on some data >>> beforesmall aftersmall >>> [1,] 63.5 512.0 >>> [2,] 54.5 237.5 >>> [3,] 52.5 161.5 >>> [4,] 78.0 153.5 >>> [5,] 53.5 68.0 >>> [6,] 50.5 65.5 >>> [7,] 69.0 52.0 >>> [8,] 76.0 59.0 >>> [9,] 68.0 66.5 >>> [10,] 75.5 66.5 >>> [11,] 67.0 45.5 >>> [12,] 81.0 54.5 >>> [13,] 49.0 44.0 >>> [14,] 51.0 42.5 >>> [15,] 53.0 34.5 >>> >>> using >>> wilcox.test(beforesmall ~ aftersmall,paired=T) >>> but I get the error message: >>> >>> Error in wilcox.test.formula(beforesmall ~ aftersmall, paired = T) : >>> grouping factor must have exactly 2 levels >>> >>> I don't have any missing values, I have the same amount of data points for >>> each group and I've looked everywhere trying to find the answer. >>> Please can somebody tell me how to make it work >>> thanks >>> >> -- Sarah Goslee http://www.functionaldiversity.org ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
